Compensating draft coupling for tractors and trailers



'w. s.' GuR'roN ET AL 1,995,920

COMPENSATING DRAFT COUPLING FOR "IRACTORS- AND TRAILERS I Maurel,I 26, 1935.

Filed oct, 21, issf 15 12 .www MA Patented Mar. 26, 1935 UNITED vvs'mcrr.

COMPENSATING DRAFT COUPLING FOR TRACTORS AND TRAILERSy William S. Gui-ton, Joseph Plint, and Herman Nyberg, Kitchener, Ontario, Canada, assignors 1 to Dominion Truck Equipment Co. Limited, l

Kitchener, Ontario, Canada Application october 21, 1933,A serial No. 694,664 'Ionian (e1. 23o-33.1)

The principal objects of this inventionare to l enable the clase-coupling of tractor and trailer units and there-1y effectively increase the carrying capacity in relation tothe over-all length of the tractor-trailer combination, and to effect a material reduction in the wind resistance encountered thereby.

The principal feature of the invention resides in the novel construction and'arrangement of parts whereby displaceable draft members normally maintain a close-coupled connection between the tractor and trailer and are automatiy cally displaced on the turning of the tractor out of alignment with the trailer to provide tuming clearance therebetween. 1 f

In the drawing, Figure 1 is'a side elevational part sectional view of a portion of a truck and trailer illustrating the present invention applied thereto.

Figure 2 is a plan view partly in section sho ing in full lines the arrangement of the coupling yelements with the tractor and trailer in alignment and illustrating in dotted linesthe disy positionof the coupling elements-whenthe tractor has assumed an angular position in turning.

' Figures 3, 4 and 5 are miniature diagrammatic y views showing the relationship' of the coupling elements when vthe trailerA is swung from its aligned position with the tractor to various angular positions.` l

It is highly desirable to enable the close-coupling lof a tractor and trailer or semi-trailer, or theclose-coupling of one trailer unit with another. f y

According to present methods of coupling however, a considerable space must be provided between the ltractor cab Aand the semi-trailer or between one trailer and another in order to pro- 'vide adequate clearancein turning so that the cab will clear theforward kcorners of thetrailer.

It has been proposed toround the entire end of the trailer unit in order to enable the vclosecoupling of the same with the tractor and to provide for the turning, but such practice is ob-l jectionable since the carrying capacity of the trailer is materially reduced.

The present invention contemplates a marked improvement in effectively overcoming the above objections, and as a means of illustrating our invention we have shown the same associated with a semi-trailer 1 having a fifth wheel form of connection with the truck or4 tractor 2.

A plate 3 is here shown anchored in any suitable manner tothe chassis 4 of the tractor and provided with upstanding bearing anges or lugs 5 disposed in spaced relation at opposite sides of thechassis centre. Y

A plate or fifth wheel member 6 is provided on which the forward end ofv the semi-trailer is adapted ,to rest,- the member 6 being here shown provided with downturned'. bearing `flanges y.'I which are pivotally connected with the upstanding flanges 5 of the trailer bymeans of the horizontal pivot bolts 8. Y

The trailer frame 9 is provided with'a cross channel membery 10 spaced yrearwardly a suitable distance from the forward channel member 11 of the frame and apair of angle. guide bars 12 are supported in spaced parallel arrangement between the members 10 and 411 and extend in a fore andaft direction.

A bearing plate member 131s rigidly secured to the underside of the frame members 101and11 andrestsin turning bearing contact on the upper surface of the fifth wheel plate 6,' the plate 13 being supported at itsouterI side edges by the frame members 14 extending between the members 10 and'll. The upper surface ofthe plate 13 is supported in spaced relation below the lower` fiangesof` the angle guide bars 12.

Extending upwardly through the plate 13 between the guide bars 12 and adjacent the forward end thereof'is a pivot bolt 15 and a linklmember 16 resting onthe upper surface of the plate 13, is provided with a boss 17 through which the boltA 15 extends, the upper end of the bolt being-firmly supported by la bracket member 18 secured to the forward member- 11 of the trailer frame.

The plate 13 is slotted to register with the guide channel formed between the members 12, vsuch slot being indicated by the` numeral 19, and a pivot pin'20` extends upwardly throghthe fifth wheel bearing plate 6 adjacent the forward edge thereof through the slot 19 and connects the '12, and a roller member 23 rotatably encircles the king bolt pin 2l and is adapted to engage.' the 40- rearward end of the link 16 withk the plate 6,

the fifth wheel plate member 6 with the plate.

3 carriedby the tractor chassis, and the traction eiortl will be transmitted from the tractor e rthrough the horizontal pivot pin 8, plate 6; pivot 20, link 16 and pivot bolt l5rto.the frame of the trailer. s

swung into angular relation to the trailer how:-

ever, it will be seen that the plate 6 will be turnedin unison with the tractor and in relation to e the trailer, such turning being about lthelrin'g pin 2l., andsince the link 16 is pivotally conf nected at its rearwardend `to the plate 6 by meansof the pin 20 vat a point forwardly of the king pin 21, the 'turning ofthetractorin the manner deflned'will cause the link 16'to be swung on its pivot 15to either one side or the other in L accordance with the angular direction assumed by the tractor,.thusl breaking the toggle 4joint vrepresented by lthelink 16 and plate 6, f The "result of this displacementis to eil'ect a shifting of the position of. the load-transmitting pivot 20l forwardly as well as laterally, clor to the forward corner 26v or 27 of the trailer in, f accordance with the direction ofturn,`and sinceV the said pivot 20 maintains a fixed distance from the rear wall 28 of the tractor cab, the forward endl of thef trailer will be bodily displacedwithrelation to the pivot 20 so that-the Icorners 26 or 27 of the trailer will beautomatically main-1 tained a clearance distance from` the wall 38 of n the cab. Thus the greater the degree of turning of the tractor relative to the cab, kthe greater will e be the swing of the link 16, and displacement of the pivot20 relative to the trailer, and since the vdistancebetween thepivot bolts 15 and 21 will.

be shortened, due to the swinging of the plate 6 and link 16, the king pin bolt 21 with its Afriction-reducing rollerA 23 will -be displaced longi-` tudinally with relationto the trailer in guidingH rolling thrust contact-with the side :walls 22 of the angle guide bars l2 while maintaining a position centrally of the width of the trailer.

With a compensating coupling such as vdescribed the trailer may be, positionedwith itsvfor-` ward end inclose relation to the rearward wall 28 of the cab, and the desired clearance will automatically be provided and increasedproportionately to the degree ofturning ofthe tractor so that it is not necessary to round away the corners 26 or 27 to any great extent andthe maximum width-of trailergmaybe used. A

It will be further evident that the close-couepling of the tractor cab and trailer body in this manner will eliminate a great amount of wind resistance, since the customary spacious recess provided rearwardly of the cab bodyA will not be presenty andaccess of head -winds tothe large" poses of illustration, a compensating coupling means interposed between a truck or tractor and a semi-trailer, it is to be understood that the invention is equally applicable to the close-coupling of two trailer units so rthat an extremely compact, train" transport willy be provided. What we^ claim'as our invention isz- 1.' The combination with a pair of transport units having the forwardfend of one resting on the other unit, of a draft connection between said units normally maintaining the same in close-coupled relation, said draft connection including. a pair of break-joint toggle members reln ativ'ely displaceable to provide a variable cou- When the tractor'is required to be turned or port units, one of said toggle members being pling distance between said close-coupled trans- `onone of said members and on which the other of said units lis adapted to rest,means forming ka displaceable turning connection between said last-mentioned transport unit kand-said plate, and link means pivotally connected with said plate in spaced; relation tothe turning connec` tiony andpivotally cor'iriec'tedl with said secondmentioned transport unitand adapted on Vthe kturning-of one-of said units relative to theother to swing the Aone unit clear ofthe other. w

Y -3. The combination with a tractorof afifth wheel plate `,mounted on the tractor .torockabout .a horizontal axis anduhaving aking. P111L ,extending upwardly therefrom, guide means extending longitudinally of the trailer and forming a thrust Iguide for said king pin to ypermit movement thereof relative to the trailer, said'trailer resting on said fifth wheel plate for turning movementv about the king pin, a link having a fixed. pivot at the forward end connecting the saine with the forward end of the trailer, and a pivot Vvconnec- -tion between the reerwerd end or saidnnkoend the forwardportion .er saidefutnwheel plete. 4.*Means as clairnedfxinA claim 3 in which a bearing plete member is interposed' between seid link and said fifth wheel plate. said platezmember being` slotted to accommodatethe jking pin and havingnarcuate slots formed therein to accommodate the p ivot connection and fifth wheel plate. y e g v A 5. A compensating draft connection for tractor andv trailer `units comprising a toggle device having one of thev toggle 'members pivotally'vyconbetween ,thelink l nected to the forward end of the trailer, the other toggle` member being pivotally andV slidably associated with the:l trailer andl alsohaving a horizontal rocking pivot connection withthe tractor and beingl constrained toturn therewith to effect apositive breaking of said toggledevice onthe turning of the tractor relative to thetrailer to provide definite turning clearance, saidv compensating draft connection beingv for the purpose of f permitting the close coupling ofithe wheeled units.' e

6. A close-couplingjcompensatingfdraft lconnection for wheeled vehicles of `the overlapped.

tractor and trailerA type comprising a pair of thrust pivots having a permanently xed spaced relation on the centre line of'one of said vehicles, said thrust pivots being respectivelyl capable of longitudinal and transverse shifting in relation to the other vehicle, 'and guide means engaging said respective thrust members to control the clearance relation of the vehicles on turning. said guide means including a member mounted on the frame of the first-mentioned vehicle between the overlapping portions of the respective vehicles and having said thrust pivots mounted thereon.

7. Means as claimed in claim 6 in which said last-mentioned member comprises a turning plate horizontally pivoted on the first-mentioned vehicle and having pivotal action about the longitudinally shiftable thrust pivot to eiect thel transverse shifting of the other thrust pivot, said longitudinally shiftable thrust pivot comprising a king pin.

WILLIAM S. GURTON. JOSEPH PLAINT.

HERMAN NYBERG. 

